Urban sprawl could power the cities of the future.

12 August 2013 — Research in Auckland, New Zealand has found that urban sprawl might be a better option than building compact cities, if solar panels are fitted on every house and electric car travel becomes the norm.

Planning focus is shifting towards building up density in cities, with the belief that tightly controlled zones are better for the environment. However research by the University of Lincoln, England in collaboration with the University of Auckland and the New Zealand Energy Centre showed that solar panels fitted to the average suburban home in Auckland could produce enough power for that household, extra to charge an electric vehicle, and still generate enough to export to the grid.

Adopting a citywide approach to fitting solar panels and providing charging points for cars would enable suburban homes to provide most of the power for the city centre as well as keeping the transport running, said Professor Hugh Byrd from the University of Lincoln’s School of Architecture.

Byrd and his colleagues found that detached suburban houses typical of a motor car age city like Auckland were capable of producing 10 times more solar power than would be possible from skyscrapers or other commercial buildings.

The calculations were based on a detailed cross section of Auckland, which has skyscrapers in its business centre but most of its homes spread out over the surrounding countryside.

Byrd said that if planners insisted on solar panels being fitted to properties and charging points be provided for electric cars, then cities judged to be damaging to the environment could be transformed.

“While a compact city may be more efficient for internal combustion engine vehicles, a dispersed city is more efficient when distributed generation of electricity by photovoltaic installations is the main energy source and electric vehicles are the principal mode of transport,” he said.

“This research could have implications on the policies of both urban form and energy. Far from reacting by looking to re-build our cities, we need to embrace the dispersed suburban areas and smart new technologies that will enable us to power our cities in a cost-effective way, without relying on ever dwindling supplies of fossil fuels.

“This study challenges conventional thinking that suburbia is energy inefficient, a belief that has become enshrined in architectural policy. In fact, our results reverse the argument for a compact city based on transport energy use, and completely change the current perception of urban sprawl.

“Photovoltaics on rooftops of course also have all the advantages of renewable energy systems, such as reduced carbon emissions, offsetting dependence on the electricity grid and long-term energy security, all of which will only become more important in cities of the future.”

Byrd conceded that the only way his ideas will work is if planning policy made fitting solar panels obligatory. Planning would also need to require the installation of photovoltaic roofing, smart meters and appropriate charging facilities for vehicles as standard in every household.

Non-energy effects of urban sprawl – including loss of wildlife habitat, decreased physical and mental health, congestion and lowered productivity – were not discussed.

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  1. “solar panels fitted to the average suburban home in Auckland could produce enough power for that household” – given most people’s electricity consumption, this would have to be a solar array (several solar panels) per household, and would need a backup for consecutive cloudy days. To say there’s plenty to also power a car and export to the grid is nonsense.

  2. The article reflects on the increasing financial attractiveness of solar PV, particularly for householders. The use of Solar PV for suburban homes should be considered during design to ensure good solar access, as it really can reduce the need for grid electricity.

    But, I think the last paragraph sums it up. There are many other reasons, apart from energy, that urban sprawl should be limited and managed.

    In Europe and many other cities around the world, you can quickly get out of a city and into the countryside by car or train. A welcome relief. I think it would be bad to have to drive through hours of suburbia to escape the city.

    Also, I don’t think the competition is between solar in suburbia and solar in cities. There are many options. For example, the 420MW Macarthur wind farm was turned on this year in Victoria and powers the equivalent of 220,000 homes.

    Solar PV and electric cars are not a good enough reason to encourage urban sprawl in my opinion.